The present invention relates to cooling of a disk array apparatus, installing therein magnetic- or optic-type disk drives in plural pieces thereof, and further, it relates to a liquid cooling apparatus for cooling heat generation, effectively, within such the apparatus with using a liquid coolant therein.
In general, the disk array apparatus is constructed by installing a large number of magnetic- or optic-type disk drives within a housing, for the purpose of increasing reliability of data reservation therein. And, those disk array apparatuses are connected with, through a high-speed network circuit for exclusive use thereof, such as, of an optic-type, etc., for example, to be operated by means of management software; i.e., they are utilized in the form of those disk apparatuses; i.e., the so-called SAN (Storage Area Network), NAS (Network Attached Storage), or an independent RAID (Redundant Array of Inexpensive Disks).
Normally, the disk drive to be installed within such the disk array apparatus comprises a disk main body, which installs a magnetic disk, a magnetic head, an actuator, etc, within an inside thereof, a package substrate, which mounts connectors thereon for connecting with electronic parts for use of control, and a canister attached with a handle or the like thereon, so that the disk main body and the package substrate mentioned above can be assembled with, and also the disk apparatus can be detached from the housing easily when conducting maintenance operation thereon.
By the way, main sources of heat generation in the disk drives mentioned above are the so-called electronic parts for control, including the drive motor, the actuator, a LSI, etc. However, those parts are cooled down through the cooling wind supplied by means of the cooling fan, which is conventionally provided within the disk array housing. For this reason, if cooling capacity thereof is bad, the temperature of the disk drive goes up, or there are generated unevenness in the temperatures among those plural numbers of disk drives, and as a result thereof, there is possibility of erroneous operations for a long time period and deterioration of reliability of the disk array apparatus.
Further, in general, as is already known by the following Patent Document 1, for example, within the conventional disk array apparatus, there is provided a fan for each of the drives, with respect to the plural pieces of disk drives within that housing, and control is made upon the fan, depending on the temperature value detected by a temperature sensor, which is provided on an outer wall of the each disk drive; thereby achieving a measure for equalizing cooling of the respective drives inside of the housing.
Or, alternately, as is already known by the following Patent Document 2, within the conventional disk array apparatus, in particular, for overcoming the problem boxes are provided, each containing the disk drives in a large number thereof within the housing, flow resistance is made smaller within an air vent passage, which is far in distance from an air blow fan provided in an upper portion of the housing; i.e., the flow resistance is made small at a downstream side within the box, thereby achieving a measure for equalizing cooling between upper and lower boxes.
Further, the following Patent Document 3 proposes a liquid cooling system, for cooling high heat-generation elements within electronic equipments, effectively or preferably, and in particular; it proposes a pump controlling method for reducing electric power consumption therein.
Patent Document 1: Japanese Patent Laying-Open No. 2000-187975 (2000);
Patent Document 2: Japanese Patent Laying-Open No. 2003-347781 (2003); and
Patent Document 3: Japanese Patent Laying-Open No. 2002-373034 (2002).
However, with the conventional art in relation to the Patent Document 1 mentioned above, since there is necessity of providing a sensor on each surface of the disk drives (in more details, on the outer wall), therefore the wiring becomes complex, within the housing, and also there is necessity of providing, as well as, a means for detecting temperature, a controller means for achieving control thereon, accompanying with it, i.e., controllers for a group of fans. For this reason, further, the temperature control in the controllers for use of the group of fans also comes to be a problem, from a viewpoint for maintaining the reliability of the disk array apparatus.
Also, with the conventional art in relation to the Patent Document 2 mentioned above, there is no such necessity of provision of the controllers for the group of fans and the controls thereof, as was mentioned above; therefore it is possible to improve the reliability of an equipment, but on the contrary thereto, there is another problem of taking a long time for adjusting the flow passages for the cooling winds within the housing, in particular, when designing the apparatus.
Further, with the conventional art in relation to the Patent Document 3 mentioned above, with using a liquid coolant therein, it is possible to obtain effects of improving the cooling performance thereof, greatly, comparing to that of the conventional air cooling method, and further increasing the lifetime of the pump, as being a driving source thereof. However, with this conventional art, the control on the pump mentioned above is achieved by using an element, which is installed in advance, into an electronic circuit board of a personal computer, such as, a keyboard controller, for example; therefore, the keyboard controller itself must be a one having special specifications thereof, so as to deal with inputs from the temperature sensors and outputs to the pumps, respectively. Also, the liquid cooling system itself must have a special input terminal, so as to input a signal from the controller mentioned above.
For this reason, with the conventional art in relation to the Patent Document 3 mentioned above, the controller mentioned above brings about an increase of cost, the control thereof becomes complex, and further problems occur with the reliability of the controller itself. As was mentioned above, a very high degree of reliability is required for the disk array apparatus or a server, and for this reason, it is necessary to study additionally the reliability factor when considering cooling of the apparatus.